DETAILED ACTION
Notice of Pre-AIA or AIA Status
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
Continued Examination Under 37 CFR 1.114
A request for continued examination under 37 CFR 1.114, including the fee set forth in 37 CFR 1.17(e), was filed in this application after final rejection. Since this application is eligible for continued examination under 37 CFR 1.114, and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114. Applicant's submission filed on January 30, 2026 has been entered.
Response to Amendment
This Office Action is in response to Applicant's amendments filed January 30, 2026. Claims 1-2 have been amended. No claims have been added. No claims have been canceled. Claims 15-20 stand withdrawn. Currently, claims 1-3, 6-7, and 21-24 are pending.
Response to Arguments
Applicant’s arguments with respect to claims 1 and 21 have been considered but are moot because the new ground of rejection does not rely on any reference applied in the prior rejection of record for any teaching or matter specifically challenged in the argument.
Claim Rejections - 35 USC § 103
The following is a quotation of 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action:
A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made.
Claims 1-2, and 6-7 are rejected under 35 U.S.C. 103 as being unpatentable over Na et al. (US 20180247968 A1) herein after “Na” in view of El Zammar et al. (US 20200144443 A1) herein after “El Zammar” and Samani et al. (US 20220336691 A1) herein after “Samani”.
Regarding claim 1, Fig. 2C of Na discloses a photodetector (Fig. 2C, photodetector 260, ¶ [0112]), comprising:
a germanium absorption region (Fig. 2C, “the absorption layer 206 is germanium”, ¶ [0102]);
an oxide layer (“a Silicon-on-Insulator (SOI) substrate includes a base layer of silicon, an insulator layer (e.g., SiO2) on the base layer of silicon, and a device layer of silicon on the layer of insulator”, ¶ [0243]); and
a silicon layer (Fig. 2C, “the substrate 202 may be a silicon substrate”, ¶ [0101]) comprising a P-type anode region (Fig. 2C, p-doped region 228, ¶ [0104]), a P-type cathode region (Fig. 2C, p-doped region 238, ¶ [0104]).
Na fails to explicitly disclose wherein the oxide layer is disposed between the germanium absorption region and a substrate; and
the silicon layer comprising a P-type region, wherein the germanium absorption region is disposed between the anode region and the cathode region.
In the similar field of endeavor of photodiodes, Figs. 3 and 13A of El Zammar discloses an oxide layer (Fig. 13A, BOX 12, ¶ [0153]), wherein the germanium absorption region (Fig. 13A, “Ge of the absorption region A”, ¶ [0238]) contacts the oxide layer (12), and wherein the oxide layer (12) is disposed between the germanium absorption region (region A) and a substrate (Fig. 3, “bulk Si 13 of the first substrate 101”, ¶ [0270]).
It would have been obvious to one of ordinary skill in the art before the time of the effective filling date of the invention to modify the photodetector of Na with the oxide layer as disclosed by El Zammar, to improve the formation of the absorption layer (see El Zammar, ¶ [0062-0063]).
El Zammar fails to disclose the silicon layer comprising a P-type region, wherein the germanium absorption region is disposed between the anode region and the cathode region.
In the similar field of endeavor of avalanche photodiodes, Fig. 10 of Samani discloses the silicon layer (Fig. 10, Si 202, ¶ [0093]) comprising a P-type region (Fig. 10, intermediate P doped silicon (P+), ¶ [0115]), wherein the germanium absorption region (Fig. 10, Ge 204, ¶ [0093]) is disposed between the P-type region (P+) and the cathode region (V1).
It would have been obvious to one of ordinary skill in the art before the time of the effective filling date of the invention to modify the photodetector of Na with the P-type region as disclosed by Samani, to improve the series resistance of the APD and decrease optical losses (see Samani, ¶ [0115]).
Regarding claim 2, Na, El Zammar and Samani together disclose the photodetector of claim 1 as applied above, but Na and El Zammar fail to disclose wherein the P-type region is between the germanium absorption region and the P-type anode region, wherein the P-type anode region is more heavily doped P-type than the P-type region.
In the similar field of endeavor of avalanche photodiodes, Fig. 10 of Samani discloses wherein the P-type region (P+) is between the germanium absorption region (204) and the P-type anode region (Fig. 10, highly P doped silicon (P++), ¶ [0114]), wherein the P-type anode region (P++ Si) is more heavily doped P-type than the P-type region (P+ Si) (“A highly P doped silicon (P++) regions”, “Intermediate P doped silicon (P+)”, ¶ [0114-0115]).
It would have been obvious to one of ordinary skill in the art before the time of the effective filling date of the invention to modify the photodetector of Na with the P-type region as disclosed by Samani, to improve the series resistance of the APD and decrease optical losses (see Samani, ¶ [0115]).
Regarding claim 6, Na, El Zammar and Samani together disclose the photodetector of claim 1 as applied above, and Na further discloses wherein the oxide layer is a buried oxide (“a Silicon-on-Insulator (SOI) substrate includes a base layer of silicon, an insulator layer (e.g., SiO2) on the base layer of silicon, and a device layer of silicon on the layer of insulator”, ¶ [0243]),
Regarding claim 7, Na, El Zammar and Samani together disclose the photodetector of claim 1 as applied above, and Na further discloses wherein the photodetector (260) is configured to generate gain when a bias voltage is applied at the P-type cathode region (238) and the P-type anode region (228) (“it is possible to apply a voltage that is less than 7 V to create an avalanche gain”, ¶ [0107]).
Claim 3 is rejected under 35 U.S.C. 103 as being unpatentable over Na (US 20180247968 A1), El Zammar (US 20200144443 A1) and Samani (US 20220336691 A1) in further view of Simoyama (US 20190378949 A1).
Regarding claim 3, Na, El Zammar and Samani together disclose the photodetector of claim 2 as applied above, but Na and El Zammar fail to disclose wherein the germanium absorption region is at least partially recessed in the silicon layer, wherein the P-type region directly contacts a first side of the germanium absorption region, and the P-type cathode region directly contacts a second side of the germanium absorption region which is opposite the first side, wherein the P-type cathode region is more heavily doped P-type than the P-type region.
In the similar field of endeavor of optical semiconductor devices, Fig. 18 of Simoyama discloses wherein the germanium absorption region (Fig. 18, Ge layer 333, ¶ [0117]) is at least partially recessed in the silicon layer (Fig. 18, Si layer 113, ¶ [0084]),
wherein the P-type region (Fig. 18, p.sup.− Si region 123, ¶ [0085]) directly contacts a first side of the germanium absorption region (333), and the P-type cathode region (Fig. 18, p.sup.− Si region 121, ¶ [0085]) directly contacts a second side of the germanium absorption region (333) which is opposite the first side.
It would have been obvious to one of ordinary skill in the art before the time of the effective filling date of the invention to modify the photodetector of Na with the arrangement and doping concentrations as disclosed by Simoyama, to improve the electrical characteristics (see Simoyama, ¶ [0118]).
Simoyama fails to disclose wherein the P-type cathode region is more heavily doped P-type than the P-type region.
In the similar field of endeavor of avalanche photodiodes, Fig. 11A of Samani further discloses wherein the P-type cathode region (P++ Si) is more heavily doped P-type than the P-type region (P+ Si) (“A highly P doped silicon (P++) regions”, “Intermediate P doped silicon (P+)”, ¶ [0114-0115]).
It would have been obvious to one of ordinary skill in the art before the time of the effective filling date of the invention to modify the photodetector of Na with the P-type region as disclosed by Samani, to improve the series resistance of the APD and decrease optical losses (see Samani, ¶ [0115]).
Claims 21-23 are rejected under 35 U.S.C. 103 as being unpatentable over Na (US 20180247968 A1) in view of Samani (US 20220336691 A1) and Joo et al. (US 20160211402 A1) herein after “Joo”.
Regarding claim 21, Fig. 2C of Na discloses a photodetector (260), comprising:
a germanium absorption region (206); and
a silicon layer (202) comprising:
a P-type anode region (228);
a P-type cathode region (238); and
an N-type region (Fig. 2C, n-well region 244, ¶ [0112]), wherein the N-type region (244) is disposed between the germanium absorption region (206) and a substrate to block current from flowing from the P-type anode region (228) to the P-type cathode region (238) (“the n-well region 244… further reduces a charge coupling from the first readout circuit 224 to the second readout circuit 234”, ¶ [0113]).
Na fails to disclose a first P-type region, wherein the germanium absorption region is disposed between the first P-type region and the cathode region;
a second P-type region, wherein the anode region and the cathode region are more heavily doped than the first and second P-type regions; and
wherein the first P-type region contacts a first side of the N-type region and the second P-type region contacts a second side of the N-type region which is opposite the first side.
In the similar field of endeavor of avalanche photodiodes, Fig. 10 of Samani discloses a first P-type region (P+), wherein the germanium absorption region (204) is disposed between the first P-type region (P+) and the cathode region (V1);
a second P-type region (P), wherein the anode region (Fig. 10, anode V4, ¶ [0093]) and the cathode region (Fig. 10, cathode V1, ¶ [0093]) are more heavily doped than the first (P+) and second P-type regions (P) (“A highly P doped silicon (P++) regions”, “Intermediate P doped silicon (P+)”, ¶ [0114-0115]).
It would have been obvious to one of ordinary skill in the art before the time of the effective filling date of the invention to modify the photodetector of Na with the P-type region as disclosed by Samani, to improve the series resistance of the APD and decrease optical losses (see Samani, ¶ [0115]).
Samani fails to disclose wherein the first P-type region contacts a first side of the N-type region and the second P-type region contacts a second side of the N-type region which is opposite the first side.
In the similar field of endeavor of photodetectors, Fig. 5 of Joo discloses wherein the first P-type region (Fig. 5, third doped region 130, ¶ [0036]) contacts a first side of the N-type region (Fig. 5, first doped region 110, ¶ [0036]) and the second P-type region (130) contacts a second side of the N-type region (110) which is opposite the first side.
It would have been obvious to one of ordinary skill in the art before the time of the effective filling date of the invention to modify the photodetector of Samani with the arrangement as disclosed by Joo, to obtain the desired electric fields (see Joo, ¶ [0038]).
Regarding claim 22, Na, Samani and Joo together disclose the photodetector of claim 21 as applied above, and Fig. 2C of Na discloses the P-type anode region (228), the P-type cathode region (238), but Na and Joo fail to disclose wherein the anode region, the cathode region, the first P-type region, and the second P-type region contacts an oxide layer.
In the similar field of endeavor of avalanche photodiodes, Fig. 10 of Samani discloses wherein the anode region (V4), the cathode region (V1), the first P-type region (P+), and the second P-type region contacts (P) an oxide layer (BOX).
It would have been obvious to one of ordinary skill in the art before the time of the effective filling date of the invention to modify the photodetector of Na with the P-type region as disclosed by Samani, to improve the series resistance of the APD and decrease optical losses (see Samani, ¶ [0115]).
Regarding claim 23, Na, Samani and Joo together disclose the photodetector of claim 22 as applied above, and Na further discloses wherein the oxide layer is a buried oxide (“a Silicon-on-Insulator (SOI) substrate includes a base layer of silicon, an insulator layer (e.g., SiO2) on the base layer of silicon, and a device layer of silicon on the layer of insulator”, ¶ [0243]).
Claim 24 is rejected under 35 U.S.C. 103 as being unpatentable over Na (US 20180247968 A1), Samani (US 20220336691 A1) and Joo (US 20160211402 A1) in further view of Simoyama (US 20190378949 A1).
Regarding claim 24, Na, Samani and Joo together disclose the photodetector of claim 21 as applied above, but Na, Samani and Joo fail to disclose wherein the germanium absorption region is at least partially recessed in the silicon layer, wherein the first P-type region directly contacts a first side of the germanium absorption region, and the P-type cathode region directly contacts a second side of the germanium absorption region which is opposite the first side.
In the similar field of endeavor of optical semiconductor devices, Fig. 18 of Simoyama discloses wherein the germanium absorption region (333) is at least partially recessed in the silicon layer (113),
wherein the first P-type region (123) directly contacts a first side of the germanium absorption region (333), and the P-type cathode region (121) directly contacts a second side of the germanium absorption region (333) which is opposite the first side.
It would have been obvious to one of ordinary skill in the art before the time of the effective filling date of the invention to modify the photodetector of Na with the arrangement and doping concentrations as disclosed by Simoyama, to improve the electrical characteristics (see Simoyama, ¶ [0118]).
Conclusion
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/C.A.N./ Examiner, Art Unit 2893
/YARA B GREEN/ Supervisor Patent Examiner, Art Unit 2893
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